Techniques for avoiding a collision between a host vehicle and an object have been proposed. For example, Patent Literature 1 discloses a device that calculates a time to an expected collision between a host vehicle and an object while considering a variation in a relative velocity Vr between the host vehicle and the object, on the basis of the relative velocity Vr, the preset amount of deceleration ΔV based on brake actuation of the host vehicle, and deceleration a based on the brake actuation of the host vehicle. The device disclosed in Patent Literature 1 calculates a timing when the time to a collision calculated in consideration of a variation in the relative velocity Vr reaches a predetermined time, as an actuation timing of the brake of the host vehicle.